Drift tube studies of large carbon clusters: New isomers and the mechanism of giant fullerene formation

Journal Article · Wed Oct 18 04:00:00 EDT 1995 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja00146a016· OSTI ID:136298

Hunter, J M; Jarrold, M F ^[1]

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1. Northwestern Univ., Evanston, IL (United States)

Injected ion drift tube techniques, including ion mobility measurements and annealing and fragmentation studies, have been used to examine even-numbered carbon cluster cations containing 100-320 atoms. The drift time distributions reveal the presence of several families of geometric isomers. The single-shell fullerene remains the dominant isomer for clusters containing up to 320 atoms. In addition, a small component of nested cage fullerenes may be present for the larger clusters. The polycyclicpolyyne ring isomers, which are abundant for clusters with less than 70 atoms, vanish at around 160 atoms. There is no evidence for the presence of long polyacetylene chains. A new family of isomers, a broad distribution with mobilities smaller than the fullerene but larger than the polycyclic rings, appears at around 100 atoms and slowly increases in relative abundance with increasing cluster size. These new isomers are probably the coalescence products of fullerenes and rings. When collisionally excited, a small fraction of these isomers readily dissociate, primarily by loss of C{sub 18} and larger even-numbered fragments, while the remainder appear to anneal into the fullerene structure. The estimated activation energy for this process is similar to the activation energy for conversion of the smaller polycyclic ring isomers into fullerenes. 48 refs., 6 figs.

• Sponsoring Organization: USDOE
• OSTI ID: 136298
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 41 Vol. 117; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
66 PHYSICS
ACTIVATION ENERGY
CARBON
DISSOCIATION
DRIFT TUBES
FULLERENES
ION DRIFT
ION MOBILITY
ISOMERS
SOLID CLUSTERS